main()//唐子豪
{
        int i,j,n=0,x;
        for(i=23;n==0;i+=2){
            for(j=1,x=i;j<=4&&x>=11;j++)
            if((x+1)%(j+1)==0)
                x-=(x+1)/(j+1);
            else {x=0;break;}
            if(j==5&&x==11){
                printf("There are %dfishes at first.\n",i);
                n=1;
            }
        }
}